MBRP Performance Exhaust 1 year warranty Better throttle response Proven HP gains on Dyno Lighter weight Easy install Stainless steel body Great MBRP Sound Direct fit to stock exhaust Trail Series 6” diameter muffler body Louder than stock 88 decibels or less at 4000 rpm Lighter thank stock Standard Series 5” muffler body louder than trail version Lighter than stock Race Series 4” diameter muffler body Loudest version of canister Very light weight Race Series